Xianqing He has uploaded this change for review. ( http://gerrit.cloudera.org:8080/17712
Change subject: IMPALA-10806: Create single node plan slowdown when hundreds of inline views are joined ...................................................................... IMPALA-10806: Create single node plan slowdown when hundreds of inline views are joined Create single node plan slowdown in the following form SQL, with about hundreds of inlineviews to join, and view1, view2... outputs hundreds of expressions. select c1 from (select c1, id from view1 where c1 > 10) t1 join (select c2, id from view2 where c1 > 10) t2 on t1.id = t2.id join ... The reasons for the slow generation of plans are 1. auxiliary predicates are added to GlobalState.conjuncts causing performance degradation of Analyzer#getUnassignedConjuncts 2. in SingleNodePlanner#createInlineViewPlan the output smap is the composition of the inline view's smap and the output smap of the inline view's plan root. Multiple inline view joins cause ExprSubstitutionMap#compose performance to degrade. For 1, add GlobalState.conjunctsWithoutAuxExpr to save the registered conjuncts without auxiliary predicate. For 2, remove expressions from outputSmap that are not used according to baseSmap. Testing: Repro query created single node plan went from 4 sec to less than 1 sec. Change-Id: Ifb4011b6167a0e61438a73c4dba6f1cd0a4e8c6a --- M fe/src/main/java/org/apache/impala/analysis/Analyzer.java M fe/src/main/java/org/apache/impala/analysis/ExprSubstitutionMap.java M fe/src/main/java/org/apache/impala/planner/SingleNodePlanner.java 3 files changed, 34 insertions(+), 4 deletions(-) git pull ssh://gerrit.cloudera.org:29418/Impala-ASF refs/changes/12/17712/1 -- To view, visit http://gerrit.cloudera.org:8080/17712 To unsubscribe, visit http://gerrit.cloudera.org:8080/settings Gerrit-Project: Impala-ASF Gerrit-Branch: master Gerrit-MessageType: newchange Gerrit-Change-Id: Ifb4011b6167a0e61438a73c4dba6f1cd0a4e8c6a Gerrit-Change-Number: 17712 Gerrit-PatchSet: 1 Gerrit-Owner: Xianqing He <[email protected]>
